> The reason is that non-quadrant arcs necessarily fall off of the > grid - in principle you can't move your crosshair their. Now that we > can snap to line/arc endpoints, this really isn't an issue, so we > can consider a more advanced arc drawing tool.
I didn't say it would be easy. Drawing programs often offer multiple ways to draw just circles; arcs add a whole new complexity to it. I can't think of a good way to have the user create non-quadrant arcs, but moving endpoints afterward might be doable. > PCB can also handle skewed arcs (unequal horizontal and vertical > axis), but that isn't supported by the gerber standard, so I proved > no way to draw them. Some of the very old libraries still do that > though. We can, at worst, convert them to line segments if we have to. > Which would have to be on a per-layer basis too. Personally I think > we should add an array of say 2 bit numbers for each layer to > indicate what style of thermal should be used on that layer. We > could offer 2 finger rotatations, solid fill, or no thermal that > way. Sounds reasonable. Fortunately, we use symbolic flags, so we can add them as new flags without breaking backward compatibility :-) We currently have: thermal(1,2,3) - thermals on layers 1, 2, and 3. We can either annotate the layers: thermal(1+,2s,3) +=rotated, s=solid or: thermal(1:rot,2:solid,3) or add a new flag name: rthermal(1) sthermal(2) thermal(3) > I think it would be nearly useless. Most boards these days have both > power and ground planes, so the vias had better clear some polys. Well, *yeah*. I meant connected vias, it would have to be part of the thermal tool. Any via with a thermal would be solid with this flag. If we do the two-bit thermal flags, this global flag would only change the default for new vias.
